/ Apparatus for separating multi frequency allocation using CQPSK/QPSK modulator/demodulator

摘要

The present invention relates to a multiple frequency allocation (FA) separation device using a complex quadrature phase shift keying (CQPSK) / QPSK modulator, and more specifically, cellular, PCS, IS configured in a mobile communication system such as CDMA and W-CDMA The present invention relates to a multi-FA separation device that can be used without loss of information when only one FA of one of -95C, IMT-2000, WLL, etc. is to be used.;A feature of the present invention is an apparatus for extracting only one FA selected from multiple FAs according to a center frequency, the apparatus comprising: a first mixer for mixing a multiple FA signal and a local signal transmitted through an input terminal; A primary PLL for processing a predetermined signal supplied to the first mixer; A first amplifier for amplifying the predetermined signal output from the primary PLL; A second amplifier for amplifying the IF signal output from the first mixer; A CQPSK / QPSK demodulator for demodulating the signal amplified by the second amplifier; A BRF for separating the base band I. Q channels of the predetermined band signal demodulated by the CQPSK / QPSK demodulator, respectively, and primary separation of adjacent FAs around the selected FA in each channel; A CQPSK / QPSK modulator that receives the I and Q signals output from the BRF and modulates them to an output terminal; A secondary PLL for supplying the predetermined signal of the CQPSK / QPSK demodulator and the CQPSK / QPSK modulator; A third amplifier for amplifying the signal output from the secondary PLL; A power divider for delivering in-phase equal amplitude power to the CQPSK / QPSK demodulator and the CQPSK / QPSK modulator, respectively; A surface acoustic wave filter for receiving a signal output through the CQPSK / QPSK modulator to improve system delay and cutoff performance; A fourth amplifier for amplifying the signal output from the surface acoustic wave filter; A second mixer for outputting the IF signal and the RF signal amplified by the fourth amplifier; A tertiary PLL for processing the predetermined signal supplied to the second mixer; And a fifth amplifier amplifying the signal output from the third PLL and sending the signal to the second mixer.;As such, the present invention can select only the desired FA among the inputted multiple FAs while minimizing the delay of the system, and the separated FA signal has excellent spurious characteristics without loss of information through modulation / demodulation and filtering processes. Therefore, there is an advantage that can maintain the formal spectral characteristics.